In the current Internet-based environment, the social network formed by online netizens has evolved beyond the simple connection between individual subscribers, and involves one-to-many and many-to-many relationships. A social network includes online users and their related networks, such as instant message (IM) systems and Internet SNS (Social Network Service) communities based on WEB2.0. Taking an IM application for example, before its subscribers intercommunicate and exchange information through their respective IM subscriber ends, the IM application typically requires certain bilateral social network relationship between the subscribers who are about to communicate with each other, in order to accelerate orientation of communicating parties and prevent subscribers from sending spam information and/or harassing messages. With the current IM software technology, if user A initiates a communication with user B who is not on a list of user A's social network relationships, or if user A requests to establish a certain social relationship with user B, user A sends an authentication request message to user B through a server system. (The authentication request message includes a textual description and user A's identification information. The identification information is used to identify a sender who sends the authentication request message. The textual description is used to express a request to establish a social network relationship with user B.) User B decides whether to establish the social network relationship with user A or not based on the authentication request message. If user B agrees then a social network relationship between user A and user B is established. If user B does not agree then a social network relationship between user A and user B cannot be established. Only after user B verifies user A's request, can user A find user B in user A's list of social network relationships, and begin to communicate and chat with user B.
When user A requests to become a user who has certain social network relationship with user B, user B can only determine, through user A's authentication request message, whether or not to establish the social network relationship with user A. Thus, under the current technologies, when user B verifies the request to establish a social network relationship with him/her, user B can only depend on the information in user A's textual description in the authentication request message forwarded by the server system to user B to make the determination. Accordingly, user B faces a problem of low authentication reliability.